91 3.1 134k misfires, kills, won't restart, will restart?

schokel

Here is the scenario:

3 days ago I come out from a store I was in, on the way the engine had been started, stop and restarted (no issues) and was fully warm when I got there.

Went to start it and it would quickly turn over, fire and then die. Tried a few times and then developed the Hmmmm factor. Next of course I did what all manly men do, popped the hood, looked for anything obvious, vacuum, disconnected anything ....... nada.

Let it cool for about 15 minutes and was able to get it to run, feathering it up through a rough beginning, ran fine, blew it out a bit on the way home, turn it off, restarted ... more hmmm factor... thought maybe "did I get an old batch of winter blend and it vapored up on me?"

A couple days later, driving (after reaching fully warm) misfire begins, kills, get it restarted, kills a couple miles later ... Done. end up getting towed.

Go out this morning, after three tries of no starting (CLUE HERE) I'm sitting there analyzing, with the key on, oil pressure gauge suddenly moves to the top, so I give it another try... It starts (roughly) runs rough at first then gets just "ok", I turn it off after a couple of minutes and of course it won't restart. (gauge does go back up again)

My Thoughts: Initially I was leaning towards electrical (weak coil pack, ignition module etc.) but then I started thinking .. Fuel clogged filter, may be pump

But I'm not so sure it's not something squirrelly like a bad ground or a intermittent short.

Thoughts??

Thanks
Dan

scott0999 · Posted: Thu Jul 03, 2008 1:42 pm Post subject:

oh boy

thats exactly what my beretta was doing while I had it

try replacing the CPS, and hope thats all it is

good luck

91z24 · Posted: Thu Jul 03, 2008 1:48 pm Post subject:

Its either CPS or ICM.

Check resistance for CPS, should be around 980ohm IIRC. If its not close to that, CPS is your problem. If it's fine, its more then likely the ICM.

schokel · Posted: Thu Jul 03, 2008 2:36 pm Post subject:

I'm leaning towards ignition control module also, since it's original failure tended to be heat related.

I'm guessing that checking and getting "weak" or dissipating spark would be my clue.

Should I replace the ... spark control module also? (why would not just be that?)

Do crank position sensors fail regularly for this engine? (never had to change one of those yet... always a first I guess)

Thanks in advance for your help,
Dan

scott0999 · Posted: Thu Jul 03, 2008 3:49 pm Post subject:

all this stuff can be checked. OHM the CPS when the car doesnt want to start. ICM can be tested at autozone ect. coilpacks can be OHM'd too

schokel · Posted: Sat Jul 05, 2008 11:45 am Post subject:

Ok Stupid question;

A few weeks ago When replacing the oil pump O-ring (the one where the distributor used to be) I obviously had to disconnect quite a few thing to get at it. Seems I inadvertently lost the blue insulating boot off of the Idle air Control valve. Could that have anything to do with it? (gets warm and maybe starts to arc)

Of course the car started once again yesterday morning, when I had a few minutes to check things, so now I'm really perplexed.

EDIT: Not IAC looks like its the Throttle position sensor that was missing the boot.

Dan

scott0999 · Posted: Sat Jul 05, 2008 12:40 pm Post subject:

schokel · Posted: Sat Jul 05, 2008 4:41 pm Post subject:

Ok I've definitely got fuel

IMHO I have more than adequate spark

But still we are at ... Turn over ... fires ... wants to start.. but cannot be feathered up in any way . (doesn't respond to accelerator action at all)

Would a failed Crank position sensor have these symptoms?

If I've got spark (checked two separate plugs) would this eliminate the Coil module and ICM (where is that any way?) ?

It acts like a bad spark advance module,

Dan

89t · Posted: Sat Jul 05, 2008 5:09 pm Post subject:

I just had a problem similar to this one.... turned out the ECM was going south. Would start rough, clear out a little, and kill itself when it got warm and failed to restart. After a cool off it would run ok, then repeat the cycle.

schokel · Posted: Sat Jul 05, 2008 8:04 pm Post subject:

(I don't think this car has an ECM..... but I'm not sure)

Well as near as I can figure, a bad Crankshaft position would yield NO spark so that doesn't fit.

I Have a Haynes book and it talks about The ALDL hook-up but does not say where it is at........ did a '91 have this? and where would it be at?

Ok I'm cool with the Coil Module (where it's at and what it does) but I still don't understand where the ignition module is in this car.

I'm getting to the point of being clueless about this problem and I've repaired way too many things to give up easily.... but I can't figure this out ..

Help!

Dan

scott0999 · Posted: Sat Jul 05, 2008 8:20 pm Post subject:

you are checking for spark when the car doesnt want to start right? just making sure lol

schokel · Posted: Sat Jul 05, 2008 9:59 pm Post subject:

schokel · Posted: Sun Jul 06, 2008 8:04 am Post subject:

OK ALDL yields nothing but 12's

But check this out ... with the jumper wire installed and the ignition the radiator fan starts running .........WTF

So it occurs to me last night ... (car won't start) I've got fuel to the schraeder, I've got spark (checked two separate plugs) but what if my injectors aren't firing.... what would prevent that??

Dan

89t · Posted: Sun Jul 06, 2008 11:54 am Post subject:

The fan will run if you jump the terminals. That is normal and a good sign.

And your car does have an ECM (it's above the glovebox), but we'll worry about that after you test the ICM.

schokel · Posted: Sun Jul 06, 2008 1:16 pm Post subject:

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